package com.huawei;

import java.io.InputStream;
import java.util.HashSet;
import java.util.Scanner;
import java.util.Set;

/**
 * Description: HJ9 提取不重复的整数
 *
 * @author weiruibai.vendor
 * Date: 2022/8/11 10:48
 */
public class HJ9 {
    public static void main(String[] args) throws Exception {

        InputStream in = System.in;
        Scanner scanner = new Scanner(in);
        int num = Integer.parseInt(scanner.next());
        Set<Integer> set = new HashSet<>();
        while (num != 0) {

            int mod = num % 10;
            if (set.add(mod)) {
                System.out.print(mod);
            }
            num = num / 10;
        }
    }
}
